Neurofibromatosis

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Neurofibromatosis
Neurofibromatosis.jpg
Back of an elderly woman with neurofibromatosis type 1
Specialty Neurosurgery, neurology, Neuro-oncology
Symptoms Small lumps within the skin, scoliosis, hearing loss, vision loss [1]
Usual onsetBirth to early adulthood [1]
DurationLife long [1]
Types Neurofibromatosis type 1 (NF1), neurofibromatosis type 2 (NF2), schwannomatosis [1]
Causes Genetic [1]
Diagnostic method Symptoms, genetic testing [2]
TreatmentSurgery, radiation therapy [2]
Prognosis NF1: variable, but most of the time normal life expectancy [1]
NF2: shortened life expectancy [1]
Frequency1 in 3,000 people (United States) [1]

Neurofibromatosis (NF) is a group of three conditions in which tumors grow in the nervous system. [1] The three types are neurofibromatosis type I (NF1), neurofibromatosis type II (NF2), and schwannomatosis. [1] In NF1 symptoms include light brown spots on the skin, freckles in the armpit and groin, small bumps within nerves, and scoliosis. [2] In NF2, there may be hearing loss, cataracts at a young age, balance problems, flesh colored skin flaps, and muscle wasting. [2] In schwannomatosis there may be pain either in one location or in wide areas of the body. [3] The tumors in NF are generally non-cancerous. [1]

Contents

The cause is a genetic mutation in certain oncogenes. [1] These can be inherited, or in about half of cases spontaneously occur during early development. [1] Different mutations result in the three types of NF. [4] Neurofibromatosis arise from the supporting cells of the nervous system rather than the neurons themselves. [1] In NF1, the tumors are neurofibromas (tumors of the peripheral nerves), while in NF2 and schwannomatosis tumors of Schwann cells are more common. [1] Diagnosis is typically based on symptoms, examination, medical imaging, and biopsy. [5] [3] Genetic testing may rarely be done to support the diagnosis. [2]

There is no known prevention or cure. [1] [2] Surgery may be done to remove tumors that are causing problems or have become cancerous. [1] Radiation and chemotherapy may also be used if cancer occurs. [1] A cochlear implant or auditory brainstem implant may help some who have hearing loss due to the condition. [1]

In the United States, about 1 in 3,500 people have NF1 and 1 in 25,000 have NF2. [1] Males and females are affected equally often. [2] In NF1, symptoms are often present at birth or develop before 10 years of age. [1] While the condition typically worsens with time, most people with NF1 have a normal life expectancy. [1] In NF2, symptoms may not become apparent until early adulthood. [1] NF2 increases the risk of early death. [1] Descriptions of the condition occur as far back as the 1st century. [6] It was formally described by Friedrich Daniel von Recklinghausen in 1882, after whom it was previously named. [4]

Signs and symptoms

Lisch nodules as seen in NF1 Lisch nodules.JPG
Lisch nodules as seen in NF1
Person with multiple small neurofibromas in the skin and a "cafe au lait spot" (bottom of photo, to the right of centre). A biopsy has been taken of one of the lesions. Early neurofibromatosis.jpg
Person with multiple small neurofibromas in the skin and a "café au lait spot" (bottom of photo, to the right of centre). A biopsy has been taken of one of the lesions.

Neurofibromatosis type 1 in early life may cause learning and behavior problems – about 60% of children who have NF1 have mild difficulty in school. [7] Signs the individual might have are as follows: [8] [9]

People with neurofibromatosis type 2 can exhibit the same type of skin symptoms as type 1, but not necessarily in every case. [10] Symptoms may include pain due to pressure on nerves, tinnitus, weakness in fingers, numbness, headaches. The symptom most characteristic of NF2 is hearing loss. [11] The hearing loss occurs due to the pressure of tumors on the acoustic nerve. The same pressure can cause headaches, dizziness, and nausea. [10]

The main symptom of schwannomatosis is localized pain. This pain is due to tissues and nerves experiencing more pressure because of nearby tumors. [12]

Cause

Diagram of autosomal dominant inheritance pattern Autosomal dominant - en.svg
Diagram of autosomal dominant inheritance pattern

The three types of neurofibromatosis are caused by different mutations on chromosomes. NF1 is caused by a mutation on the NF1 gene on the arm of chromosome 17. [4] NF2 is caused by a mutation on the NF2 tumor suppressor gene on chromosome 22. [4] Schwannomatosis is caused by various mutations on chromosome 22. [4]

Neurofibromatosis is an autosomal dominant disorder, which means only one copy of the affected gene is needed for the disorder to develop. [4] If one parent has neurofibromatosis, his or her children have a 50% chance of developing the condition as well. The severity of the parent's condition does not affect the child; the affected child may have mild NF1 even though it was inherited from a parent with a severe form of the disorder. [14] The types of neurofibromatosis are:

Pathophysiology

The pathophysiology is varied, and each NF type has a different one:

Diagnosis

The neurofibromatoses are considered as RASopathies and as members of the neurocutaneous syndromes (phakomatoses). [23] The diagnosis of neurofibromatosis is done via the following means: [24]

Differential diagnosis

Conditions similar to NF include:

Treatment

Surgical removal of tumors is an option; however, the risks involved should be assessed first. [28] With regard to OPG (optic pathway gliomas), the preferred treatment is chemotherapy. However, radiotherapy is not recommended in children who present with this disorder. [29] It is recommended that children diagnosed with NF1 at an early age have an examination each year, which allows any potential growths or changes related to the disorder to be monitored. [30]

Prognosis

In most cases, symptoms of NF1 are mild, and individuals live normal and productive lives. In some cases, however, NF1 can be severely debilitating and may cause cosmetic and psychological issues. The course of NF2 varies greatly among individuals. In some cases of NF2, the damage to nearby vital structures, such as other cranial nerves and the brain stem, can be life-threatening. Most individuals with schwannomatosis have significant pain. In some extreme cases, the pain will be severe and disabling. [9]

Epidemiology

In the United States, about 1 in 3,500 people have NF1, 1 in 25,000 have NF2, and 1 in 40,000 have schwannomatosis. [1] Males and females are affected equally often in all three conditions. [2] In NF1, symptoms are often present at birth or develop before 10 years of age. [1] While the condition typically worsens with time, most people with NF1 have a normal life expectancy. [1] In NF2, symptoms may not become apparent until early adulthood. [1] NF2 increases the risk of early death. [1] Schwannomatosis symptoms develop in early childhood and can worsen with time. Typically life expectancy is unaffected in those with schwannomatosis. [3]

History

Descriptions of what is believed to be the condition go as far back as the 1st century. [6] The conditions were formally described by Friedrich Daniel von Recklinghausen in 1882, after whom it was previously named. [4]

Related Research Articles

<span class="mw-page-title-main">Genetic disorder</span> Health problem caused by one or more abnormalities in the genome

A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a chromosomal abnormality. Although polygenic disorders are the most common, the term is mostly used when discussing disorders with a single genetic cause, either in a gene or chromosome. The mutation responsible can occur spontaneously before embryonic development, or it can be inherited from two parents who are carriers of a faulty gene or from a parent with the disorder. When the genetic disorder is inherited from one or both parents, it is also classified as a hereditary disease. Some disorders are caused by a mutation on the X chromosome and have X-linked inheritance. Very few disorders are inherited on the Y chromosome or mitochondrial DNA.

<span class="mw-page-title-main">Proteus syndrome</span> Human genetic disorder

Proteus syndrome is a rare disorder with a genetic background that can cause tissue overgrowth involving all three embryonic lineages. Patients with Proteus syndrome tend to have an increased risk of embryonic tumor development. The clinical and radiographic symptoms of Proteus syndrome are highly variable, as are its orthopedic manifestations.

<span class="mw-page-title-main">Noonan syndrome</span> Genetic condition involving facial, heart, blood and skeletal features

Noonan syndrome (NS) is a genetic disorder that may present with mildly unusual facial features, short height, congenital heart disease, bleeding problems, and skeletal malformations. Facial features include widely spaced eyes, light-colored eyes, low-set ears, a short neck, and a small lower jaw. Heart problems may include pulmonary valve stenosis. The breast bone may either protrude or be sunken, while the spine may be abnormally curved. Intelligence is often normal. Complications of NS can include leukemia.

<span class="mw-page-title-main">Neurofibromatosis type I</span> Type of neurofibromatosis disease

Neurofibromatosis type I (NF-1), or von Recklinghausen syndrome, is a complex multi-system human disorder caused by the mutation of neurofibromin 1 (NF-1), a gene on chromosome 17 that is responsible for production of a protein (neurofibromin) which is needed for normal function in many human cell types. NF-1 causes tumors along the nervous system which can grow anywhere on the body. NF-1 is one of the most common genetic disorders and is not limited to any person's race or sex. NF-1 is an autosomal dominant disorder, which means that mutation or deletion of one copy of the NF-1 gene is sufficient for the development of NF-1, although presentation varies widely and is often different even between relatives affected by NF-1.

In genetics, expressivity is the degree to which a phenotype is expressed by individuals having a particular genotype. Alternatively, it may refer to the expression of a particular gene by individuals having a certain phenotype. Expressivity is related to the intensity of a given phenotype; it differs from penetrance, which refers to the proportion of individuals with a particular genotype that share the same phenotype.

<span class="mw-page-title-main">Malignant peripheral nerve sheath tumor</span> Medical condition

A malignant peripheral nerve sheath tumor (MPNST) is a form of cancer of the connective tissue surrounding nerves. Given its origin and behavior it is classified as a sarcoma. About half the cases are diagnosed in people with neurofibromatosis; the lifetime risk for an MPNST in patients with neurofibromatosis type 1 is 8–13%. MPNST with rhabdomyoblastomatous component are called malignant triton tumors.

<span class="mw-page-title-main">Neurofibromatosis type II</span> Type of neurofibromatosis disease

Neurofibromatosis type II is a genetic condition that may be inherited or may arise spontaneously, and causes benign tumors of the brain, spinal cord, and peripheral nerves. The types of tumors frequently associated with NF2 include vestibular schwannomas, meningiomas, and ependymomas. The main manifestation of the condition is the development of bilateral benign brain tumors in the nerve sheath of the cranial nerve VIII, which is the "auditory-vestibular nerve" that transmits sensory information from the inner ear to the brain. Besides, other benign brain and spinal tumors occur. Symptoms depend on the presence, localisation and growth of the tumor(s), in which multiple cranial nerves can be involved. Many people with this condition also experience vision problems. Neurofibromatosis type II is caused by mutations of the "Merlin" gene, which seems to influence the form and movement of cells. The principal treatments consist of neurosurgical removal of the tumors and surgical treatment of the eye lesions. Historically the underlying disorder has not had any therapy due to the cell function caused by the genetic mutation.

<span class="mw-page-title-main">Neurofibroma</span> Medical condition

A neurofibroma is a benign nerve-sheath tumor in the peripheral nervous system. In 90% of cases, they are found as stand-alone tumors, while the remainder are found in persons with neurofibromatosis type I (NF1), an autosomal-dominant genetically inherited disease. They can result in a range of symptoms from physical disfiguration and pain to cognitive disability.

Phakomatoses, also known neurocutaneous syndromes, are a group of multisystemic diseases that most prominently affect structures primarily derived from the ectoderm such as the central nervous system, skin and eyes. The majority of phakomatoses are single-gene disorders that may be inherited in an autosomal dominant, autosomal recessive or X-linked pattern. Presentations may vary dramatically between patients with the same particular syndrome due to mosaicism, variable expressivity, and penetrance.

The Crowe sign or Crowe's sign is the presence of axillary (armpit) freckling in people with neurofibromatosis type I. These freckles occur in up to 30% of people with the disease and their presence is one of six diagnostic criteria for neurofibromatosis. Freckles can also be present in the intertriginous area in neurofibromatosis, such as the inguinal fold, submammary areas, and nape of the neck.

<span class="mw-page-title-main">Children's Tumor Foundation</span>

The Children's Tumor Foundation (CTF) is a 501(c)(3) foundation dedicated to improving the health and well-being of individuals and families affected by NF, a group of genetic conditions known as neurofibromatosis or schwannomatosis. Their four-part mission includes propelling drug research and development through a series of strategic investments, strengthening patient support, increasing public awareness of NF and establishing best practices in clinical care for affected individuals. The Foundation is incorporated in all 50 states with active chapters and affiliates in 37 states. CTF is the largest private funder of all forms of NF research.

<span class="mw-page-title-main">Costello syndrome</span> Medical condition

Costello syndrome, also called faciocutaneoskeletal syndrome or FCS syndrome, is a rare genetic disorder that affects many parts of the body. It is characterized by delayed development and intellectual disabilities, distinctive facial features, unusually flexible joints, and loose folds of extra skin, especially on the hands and feet. Heart abnormalities are common, including a very fast heartbeat (tachycardia), structural heart defects, and overgrowth of the heart muscle. Infants with Costello syndrome may be large at birth, but grow more slowly than other children and have difficulty feeding. Later in life, people with this condition have relatively short stature and many have reduced levels of growth hormones. It is a RASopathy.

<span class="mw-page-title-main">Merlin (protein)</span> Mammalian protein found in Homo sapiens

Merlin is a cytoskeletal protein. In humans, it is a tumor suppressor protein involved in neurofibromatosis type II. Sequence data reveal its similarity to the ERM protein family.

<span class="mw-page-title-main">Schwannomatosis</span> Rare genetic disorder

Schwannomatosis is an extremely rare genetic disorder closely related to the more-common disorder neurofibromatosis (NF). Originally described in Japanese patients, it consists of multiple cutaneous schwannomas, central nervous system tumors, and other neurological complications, excluding hallmark signs of NF. The exact frequency of schwannomatosis cases is unknown, although some populations have noted frequencies as few as 1 case per 1.7 million people.

<span class="mw-page-title-main">Noonan syndrome with multiple lentigines</span> Rare autosomal dominant multi-system genetic condition

Noonan syndrome with multiple lentigines (NSML) which is part of a group called Ras/MAPK pathway syndromes, is a rare autosomal dominant, multisystem disease caused by a mutation in the protein tyrosine phosphatase, non-receptor type 11 gene (PTPN11). The disease is a complex of features, mostly involving the skin, skeletal and cardiovascular systems, which may or may not be present in all patients. The nature of how the mutation causes each of the condition's symptoms is not well known; however, research is ongoing. It is a RASopathy.

<span class="mw-page-title-main">Neurofibromin 1</span> Mammalian protein found in Homo sapiens

Neurofibromin 1 (NF1) is a gene in humans that is located on chromosome 17. NF1 codes for neurofibromin, a GTPase-activating protein that negatively regulates RAS/MAPK pathway activity by accelerating the hydrolysis of Ras-bound GTP. NF1 has a high mutation rate and mutations in NF1 can alter cellular growth control, and neural development, resulting in neurofibromatosis type 1. Symptoms of NF1 include disfiguring cutaneous neurofibromas (CNF), café au lait pigment spots, plexiform neurofibromas (PN), skeletal defects, optic nerve gliomas, life-threatening malignant peripheral nerve sheath tumors (MPNST), pheochromocytoma, attention deficits, learning deficits and other cognitive disabilities.

<span class="mw-page-title-main">Legius syndrome</span> Medical condition

Legius syndrome (LS) is an autosomal dominant condition characterized by cafe au lait spots. It was first described in 2007 and is often mistaken for neurofibromatosis type I. It is caused by mutations in the SPRED1 gene. It is also known as neurofibromatosis type 1-like syndrome.

<span class="mw-page-title-main">SPRED1</span> Protein-coding gene in the species Homo sapiens

Sprouty-related, EVH1 domain-containing protein 1 (Spread-1) is a protein that in humans is encoded by the SPRED1 gene located on chromosome 15q13.2 and has seven coding exons.

The RASopathies are a group of developmental syndromes caused by germline mutations in genes belonging to the Ras/MAPK pathway. Common features include intellectual disability, congenital heart defects, skin abnormalities, and craniofacial abnormalities.

<span class="mw-page-title-main">Ring chromosome 22</span> Rare chromosomal disorder

Ring chromosome 22, also known as ring 22, is a rare chromosomal disorder. Ring chromosomes occur when the ends of a chromosome lose material and fuse into a ring shape; in the case of ring 22, this occurs for chromosome 22, the last numbered human autosome. Ring chromosome 22 is marked by a number of consistent traits, such as intellectual disability, speech delay, hypotonia, and hyperactivity. The condition has a similar phenotype to Phelan-McDermid syndrome, as the loss of the SHANK3 gene is implicated in both.

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 "Neurofibromatosis Fact Sheet". NINDS. 3 February 2016. Archived from the original on 23 January 2018. Retrieved 16 April 2018.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  2. 1 2 3 4 5 6 7 8 "Learning about Neurofibromatosis". National Human Genome Research Institute (NHGRI). 16 August 2016. Archived from the original on 10 October 2016. Retrieved 7 November 2016.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  3. 1 2 3 Dhamija R, Plotkin S, Asthagiri A, Messiaen L, Babovic-Vuksanovic D, Adam MP, Mirzaa GM, Pagon RA, Wallace SE, Bean LJH, Gripp KW, Amemiya A (1993). "Schwannomatosis". GeneReviews®. University of Washington, Seattle. PMID   29517885 . Retrieved 21 November 2019.
  4. 1 2 3 4 5 6 7 Woodrow C, Clarke A, Amirfeyz R (1 June 2015). "Neurofibromatosis". Orthopaedics and Trauma. 29 (3): 206–210. doi:10.1016/j.mporth.2015.02.004. ISSN   1877-1327. S2CID   239484110 . Retrieved 22 November 2019.
  5. Le C, Bedocs PM (January 2019). "Neurofibromatosis". PMID   29083784.{{cite journal}}: Cite journal requires |journal= (help)
  6. 1 2 Ferner RE, Huson S, Evans DG (2011). Neurofibromatoses in clinical practice. London: Springer. p. 1. ISBN   978-0-85729-628-3. Archived from the original on 10 September 2017. Retrieved 9 October 2015.
  7. "Neurofibromatosis". NHS Choices. NHS. Archived from the original on 25 September 2015. Retrieved 9 October 2015.
  8. "Neurofibromatosis". NINDS. NIH. Archived from the original on 4 October 2015. Retrieved 9 October 2015.
  9. 1 2 "NINDS Neurofibromatosis Information Page". 23 February 2015. Archived from the original on 4 April 2015. Retrieved 21 April 2015.
  10. 1 2 Guha M (March 2011). Fundukian LJ (ed.). "The Gale Encyclopedia of Genetic Disorders". Reference Reviews (3rd ed.). Detroit, MI: Gale. 25 (3): 40–42. doi:10.1108/09504121111119022. ISBN   978-1-4144-7602-5.
  11. Selvanathan SK, Shenton A, Ferner R, Wallace AJ, Huson SM, Ramsden RT, Evans DG (11 January 2010). "Further genotype – phenotype correlations in neurofibromatosis 2". Clinical Genetics. 77 (2): 163–170. doi:10.1111/j.1399-0004.2009.01315.x. ISSN   0009-9163. PMID   19968670. S2CID   11130733.
  12. 1 2 3 4 5 Plotkin SR, Blakeley JO, Evans DG, Hanemann CO, Hulsebos TJ, Hunter-Schaedle K, et al. (March 2013). "Update from the 2011 International Schwannomatosis Workshop: From genetics to diagnostic criteria". American Journal of Medical Genetics. Part A. 161A (3): 405–416. doi:10.1002/ajmg.a.35760. PMC   4020435 . PMID   23401320.
  13. Bachir S, Shah S, Shapiro S, Koehler A, Mahammedi A, Samy RN, et al. (2021). "Neurofibromatosis Type 2 (NF2) and the Implications for Vestibular Schwannoma and Meningioma Pathogenesis". Int J Mol Sci. 22 (2): 690. doi: 10.3390/ijms22020690 . PMC   7828193 . PMID   33445724.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  14. "Neurofibromatosis type 1 - Causes". NHS Choices. Archived from the original on 24 September 2015. Retrieved 9 October 2015.
  15. "Neurofibromatosis type 1". Genetics Home Reference. 5 October 2015. Archived from the original on 10 September 2015. Retrieved 9 October 2015.
  16. "Neurofibromatosis type 2". Genetics Home Reference. 5 October 2015. Archived from the original on 10 September 2015. Retrieved 9 October 2015.
  17. Perry A, Brat DJ (1 January 2010). Practical Surgical Neuropathology: A Diagnostic Approach. Elsevier Health Sciences. p. 435. ISBN   978-0443069826. Archived from the original on 2 May 2016.
  18. Wallace MR, Marchuk DA, Andersen LB, Letcher R, Odeh HM, Saulino AM, Fountain JW, Brereton A, Nicholson J, Mitchell AL, Brownstein BH, Collins FS (13 July 1990). "Type 1 Neurofibromatosis Gene: Identification of a Large Transcript Disrupted in Three NF1 Patients". Science. 249 (4965): 181–186. doi:10.1126/science.2134734. ISSN   0036-8075. PMID   2134734.
  19. "Orphanet: Neurofibromatosis type 1". www.orpha.net. Archived from the original on 6 October 2015. Retrieved 13 October 2015.
  20. 1 2 3 4 Ferner RE (February 2007). "Neurofibromatosis 1". European Journal of Human Genetics. 15 (2): 131–138. doi: 10.1038/sj.ejhg.5201676 . PMID   16957683.
  21. Boyd KP, Korf BR, Theos A (July 2009). "Neurofibromatosis type 1". Journal of the American Academy of Dermatology. 61 (1): 1–14. doi:10.1016/j.jaad.2008.12.051. PMC   2716546 . PMID   19539839.
  22. 1 2 3 4 Lin AL, Gutmann DH (November 2013). "Advances in the treatment of neurofibromatosis-associated tumours". Nature Reviews. Clinical Oncology. 10 (11): 616–624. doi:10.1038/nrclinonc.2013.144. PMID   23939548. S2CID   21986493.
  23. Fischer C, Bagheri F, Manchandani R, Pinsker R, Chauhan S, Patel P, et al. (2010). Master the Board USMLE Step 2 CK. KAPLAN Medical. p. 287. ISBN   978-1-60714-653-7.
  24. "Neurofibromatosis. What is neurofibromatosis? Type 1 (NF1) | Patient". Patient. Archived from the original on 4 October 2015. Retrieved 9 October 2015.
  25. Friedman JM (2014). Adam MP, Ardinger HH, Pagon RA, Wallace SE, Bean LJ, Gripp KW, Mirzaa GM, Amemiya A (eds.). Neurofibromatosis 1. Seattle (WA): University of Washington, Seattle. PMID   20301288. Archived from the original on 18 January 2017.
  26. Legius E, Stevenson D (2015). Adam MP, Ardinger HH, Pagon RA, Wallace SE, Bean LJ, Gripp KW, Mirzaa GM, Amemiya A (eds.). Legius Syndrome. Seattle (WA): University of Washington, Seattle. PMID   20945555. Archived from the original on 10 September 2017.
  27. El-Sobky TA, Elsayed SM, El Mikkawy DM (December 2015). "Orthopaedic manifestations of Proteus syndrome in a child with literature update". Bone Reports. 3: 104–108. doi:10.1016/j.bonr.2015.09.004. PMC   5365241 . PMID   28377973.
  28. "Neurofibromatosis type 2 - Treatment". NHS Choices. Archived from the original on 22 December 2015. Retrieved 11 October 2015.
  29. "Complex Neufibrmatosis type 1" (PDF). NHS.uk. NHS. Archived (PDF) from the original on 23 December 2015. Retrieved 13 October 2015.
  30. "Neurofibromatosis type 1 - Treatment". NHS Choices. Archived from the original on 26 September 2015. Retrieved 11 October 2015.

Further reading